Accelerating blasting plug



April 5, 1938., A, F, DIETZ 2,12,906

ACCELERATING BLASTING PLUG Filed June 5, 1955 Patented Apr. s, 193s 2,112,906

`UNITED STATES PATENT OFFICE aliasos ACCELERATING BLASTING PLUG Alin F. Dietz, Shamokin, Pa.

Application June 5, 1935, Serial N0. 25,158

2 Claims. (Cl. 102-11) This invention relates to a blasting plug with Figure 3 is a side sectional view of the blasting one or more accelerator chambers and it has for plug of my invention in normal or unexpanded its general object the employment of the blastcondition; ing plug as the carrier of one or more small Figure 4 is a similar view showing the insert 5 vessels containing an accelerator for the explodriven home and the walls of the plug expanded; 5

sion and which may itself be an explosive such Figure 5 is an inner end view; as nitroglycerin, or preferably, in the interest of Figure 6 is a longitudinal section through a safety in storing and use, a non-explosive which capsule adapted to contain liquid oxygen or other is a. supporter of combustion, such as liquid accelerant; and

10 oxygen. Figure 7 is an axial section through the end of 10 The invention preferably utilizes a soft rubber the blasting plug showing the soft rubber replug of the type disclosed in Patent No. 2,007,568, taining flange surrounding the mouth of the c apgranted July 9, 1935, to Richard J. Heitzm'an, sule receiving recess. which includes a tapered insert by means of Referring now in detail to .the several gures l5 which the plug is expanded into sealing relation the numeral l represents a blasting plug which l5 to the wall of a drilled hole by pressure of a may be of rubber or any substance having similar tamping rod, and which at .the instant of the exqualities of elastic deformation having a recess plosion is further expanded into sticking contact 2 in its outer end in which is seated a conical with the Wall of the bore through the explosion insert 3. The insert 3 is preferably of herder pressure, reacting with a cushioning function substance than the rubber so that as the insert 26 upon the explosion which reduces the shatteris forced into the recess 2 the wall of the recess 2 ing effect and brings down a greater proportion Will be expanded outward. When this is done of large pieces of ,the blasted material. in a drilled hole in the coal or rock, the yielding One of the objects of the invention is to prowall of the recess 2 is forced into intimate convide one or more cells in the advance end of the tact with the wall of the drilled hole along the 25 plug adapted to contain directly or in suitable Zone indicated at 4 in Figure l. This not only vesse1s, a charge of the acce1erating substance. seals the explosive from the atmosphere in e per- Another object of the invention is the provifectly gas-tight manner, but also retains the plug sion in the inner end of a plug of the class dein the hole up to the peak period of .the exploscribed, of one or more recesses having elastic Sion. thuS obviating the need 0f Stemming walls adapted to receive and retain a small vessel which characterizes the customary Practice of or vessels holding the accelerant. placing a charge in blasting, particularly in coal Still another object of .the invention is to promines. vide a blasting plug ofv soft rubber or similar At the instant of explosion .the inner end 5 of substance having recesses inits inner end adaptthe plug iS forced beek. Spreading the rubber 35 ed to facilitate the bulging of said plug into betradially So that the inner end of the plug makes ter sealing contact with the wall of the drilled sticking contact with the wail of the drilled hole hole at the instant of explosion, as well as to along the Zone 5 in Figure 2- Thus at the inconstitute an air cushion for dampening the Stent 0f explosion the Plug iS doulillir Sealed shattering effect ofthe explosion. against the escape of eases and held in place 40 Other objects of the invention will appear as long enough to permit the fol'oe 0f the explosion the following description of a preferred and to be extended upon the Surrounding e081 or practical embodiment thereof proceeds, rock. The recession of the inner end 5 under In the drawing which accompanies and forms the explosion pressure exercises a cushioning a part of the following specification and througheffect upon the impact of the eXploSlon. reducing 45 out the several figures of which the same charits shattering qualltieS S0 that greater Proporacters of reference have been employed to desigtion of large Dleoe-S of blasted materiel iS thrown nate identical parts: down. than is customary with ordinary methods Figure 1 is an axial section through a drilled of blasting.

hole in rock or coal showing a blasting plug em- Such plugs are known, being disclosed and 50 bracing the features of my invention sealing the claimed in the application for patent to Heitzman hole in advance of the explosion charge; aforementioned. My improvement begins with Figure 2 is -a similar View showing conditions the provision in the anterior end of the plug of at the instant of explosion lust before disruption one or more bores or recesses 1, preferably of of the plug; cylindrical form for ease of manufacture. Figure 55 5 shows that three such recesses are contemplated in the illustrative embodiment of the invention. 'Ihe number of recesses however is immaterial and may vary from a single recess to as large a number as is practical with respect to the area of the inner end of the plug.

' 'Ihese recesses 'l serve several new and advantageous functions. In the rst place, by perforating the mass of rubber in the anterior end of the plug they make it easier for the plug to spread lunder the explosion pressure extending the zone of sealing contact between the anterior end of the plug and the surrounding wall of the drilled hole. They also constitute air cushions, the inert air in them yielding directly to the explosion pressure.

Thus, although the recesses are primarily intended for the reception of capsules or other suitable vessels of accelerant, they have a decided utility even when the plug is employed without any accelerant. The accelerating substance may be of any substantial nature as has been indicated, for example, it may be a charge of nitroglycerin. This might be poured directly into the recesses 1 and said recesses corked before the plug is thrust home in the drilled hole. The softness and yielding characteristic of which the plug is made would preclude the premature uniting of the nitroglycerin through tamping pressure necessary to seat the plug. Preferably the nitroglycerin would already be packed in small ampuls or capsules such as the capsule 8 shown in Figure 3 and one or more of these capsules may be inserted in the recesses at the time of placing the charge. However, nitroglycerin at best is an uncertain and unsafe substance to handle and it is preferred to use an accelerant which is in itself inexplosive, but which will support combustion and in that way add to the power of the explosion. Oxygen is suggested as a safe accelerant of this nature ,and in order to get enough of it into the drilled hole it would have to be supplied in liquid form. Figure 6 shows a fluid-tight capsule 8 which may be glass and containing liquid oxygen. The ampul 8 is shown as being blown and filled like an electric light bulb with a fused teat 9 on the end. By approved methods of manufacture, this teat could be omitted and the capsule be of' uniform contour throughout. In place of the capsule, an ordinary small bottle with sealed stopper may serve as the container of the oxygen. Regardless of the type of container of acoelerant, the recesses 1 are preferably so shaped as to t and retain the capsule. Since the walls of the recesses 1 are of yielding elastic, the recesses may, if desired, be made slightly smaller than Hic capsule and the latter forced into the recess being retained by frictional pressure. Or, as shown in Figure 7 the mouths of the recesses may be provided with a surrounding yielding integral flange l0 of rubber through which the capsule may be pressed into said recess, and after it has entered said recess the flange l0 will spring out in front of the capsule and keep it from being displaced. In use, the explosion is produced in the customary manner and immediately shatters the capsule freeing the oxygen which accelerates the power of the explosion.

The plugs can be made and sold ready loaded with the capsules or a supply of such capsules may be kept on hand and the plugs lled with the charged vessels before being inserted into the drilled hole.

Although I have illustrated my invention with a somewhat specific form of the invention, it Will be understood to those skilled in the art that the details of construction are merely by way of example and not to be construed as limiting the scope of the appended claims.

What I claim is:

1. Blasting plug comprising a cylindrical member of a material having the quality of elastic deformation comparable with that of soft rubber, having a recess at its outer end and an expander in said recess for expanding the periphery of said member into sealing relation to a drilled hole in coal or rock, the inner end of said member being deformable under pressure to form an auxiliary peripheral seal to cushion the impact of the explosion, said inner end being formed with one or more flexible walled chambers opening at the face of the inner end and a normally sealed vessel containing an explosion accelerant for the said charge, said accelerant being liberated from said vessel by the shock of the explosion.

2. Blasting plug comprising a cylindrical member of a material having the quality of elastic deformation comparable with that of soft rubber, having a recess at its outer end and an expander in said recess for expanding the peripheral wall of said member into sealing relation to the drilled hole in coal or rock, the inner end of said member being deformable under pressure to form an auxiliary peripheral seal and to cushion the impact of the explosion, said inner end being formed with one or more chambers opening at the face of said inner end, and one or more vessels of an explosion accelerant positioned in said chambers, the mouths of said chambers being provided with integral flexible flanges functioning as check valves permitting the insertion of said vessels into said chambers, but preventing their free escape therefrom.

ALVIN F. DIE'IZ. 

